peridocitiy period 3

Question 1

why does sodium oxide form an alkali solution when it reacts with water?

Answer 1

sodium oxide contains O2- ions those O2- ions react with water forming OH- ions

Question 2

why does silicon dioxide have a high melting point

Answer 2

• It has a macromolecular structure
• contains covalent bonds between molcules
• many strong covalent bonds that need to be broken

Question 3

give a few characteristics of silicon dioxide

Answer 3

it is brittle a non conductor and insoluble

Question 4

What is amphoteric

Answer 4

It can act as both acid or base/alkali

Question 5

what is the reaction of sodium in air like

Answer 5

vigorous

produces a yellow flame

Question 6

what is the reaction of magnesium in air like

Answer 6

vigorous

produces a brilliant white flame

Question 7

what is the reaction of aluminium and silicion in air like

Answer 7

they are both slow and don’t produce a flame

Question 8

what is the reaction of phosphorous in air like

Answer 8

it spontaneously combusts and produces a brilliant white flame

Question 9

what is the reaction of sulfur in air like

Answer 9

it burns steadily

produces a blue flame

Question 10

what is the product of the reactions of sodium with water

Answer 10

for sodium:
sodium hydroxide NaOH
and hydrogen

Question 11

what are the products for the two different reactions of magnesium and water

Answer 11

with cold water: 
magensium hydroxide Mg(OH)2 
hydrogen
with steam:
magnesium oxide MgO 
hydrogen

Question 12

what are the pH values for magnesium and sodium hydroxide

Answer 12

Sodium hydroxide: 12-14

magnesium hydroxide: 9-10

Question 13

what is the product of the reaction of sulfur dioxide with water

Answer 13

sulfurous acid H2SO3

Question 14

what is the product of the reaction of sulfur troxide with water

Answer 14

sulfuric acid H2SO4

Question 15

what is periodicity

Answer 15

a regularly repeating pattern of atomic, physical, and chemical properties with increasing atomic number